In an ordinary keyed instrument, natural keys are disposed for natural tones and chromatic keys are disposed for their derivative tones. Accordingly, when flat families or sharp families are played in this kind of instrument, transposed tones require the use of chromatic keys. For example, C, D, E, F, G, A, B, C in the case of C major are played by pressing natural keys. However, D major begins with the D tone. Accordingly, natural keys and chromatic keys must be pressed. Thus, the operation of chromatic keys is required for transposition and this applies also to the case of all electronic musical instruments. Thus, playing with transposition is very difficult for a beginner.